(1) Why is the Schwartzian transform read from bottom to top? Since in procedural programming it's usually top to bottom. Reading the Wikipedia article it makes sense however curious as to the behavior of this method.

(2)Could you please explain the expression used in map{}?
{ my $stat = stat $_; [ $_, $stat->mtime ] }
I understand that a scalar variable called $stat has been defined to the 'default variable' $_. My understanding is that when map() is run (the map on the bottom) it evaluates the expression within {} for each element in @fileNames and stores it in the default variable? So would this mean that each time an element is passed the default variable changes?

(3) Further to (2), I understand that "$stat->mtime" is getting the last modified time since epoch for each value of $stat, my understanding is that each time the next element from the array is passed the mtime for that particular $stat is obtained. So what's the meaning of [ $_, $stat->mtime ]. Since there's a comma separating the two.

(4) The semicolon in { my $stat = stat $_; [ $_, $stat->mtime ] } is separating the two statements within this single expression. Is that correct?

(5)
I understand that in sort { $b->[1] <=> $a->[1] } a descending numeric sort is being performed. However what I don't get is the [1] $b and $a both share. Also what's the relationship between $b and $a? I found an example of this type of sort on the net however it did not explain why $b and $a are used. Do they simply represent two different locations in a list?

(6)The map $_->[0] does not appear to follow the format map({expression}, list). How is this different to the standard map function?

Thanks for your help! Sorry for these questions just clarifying my doubts.

Ada Lovelace for the palindrome
Albert Einstein for having smelly feet
Alfred Nobel for his contribution to battlefield science
Burkhard Heim for providing the missing link between science and mysticism
Claude Shannnon for riding a unicycle at night at MIT
Donald Knuth for being such a great organist
Edward Teller for being the template for Dr. Strangelove
Edwin Hubble for pretending to be a pipe-smoking English gentleman
Erwin Schrödinger for cruelty to cats
Hedy Lamarr for weaponizing pianos
Hugh Everett for immortality, especially for cats
Isaac Newton for his occult studies
Kikunae Ikeda for discovering the secrets of soy sauce
Larry Wall for his website
Louis Camille Maillard for discovering why steaks taste good
Marie Curie for the shiny stuff
Nikola Tesla for the cool cars
Paul Dirac for speaking one word per hour when socializing
Richard Feynman for his bongo skills
Robert Oppenheimer for his in-depth knowledge of the Bhagavad Gita
Rusi P Taleyarkhan for Cold Fusion
Sigmund Freud for his Ménage ā trois
Theodor W Adorno for his contribution to the reception of jazz
Wilhelm Röntgen for the foundations of body scanners
Yulii Borisovich Khariton for the Tsar Bomba
Other (please explain why)